Electrical musical instrument with vibratory strings



Sept. 25, 1951 c, MARTIN ELECTRICAL MUSICAL. INSTRUMENT WITH Filed Aug.13, 1947 VIBRATORY STRINGS 5 Sheets-Sheet l N m LL] E a m E 5 R E 5 0 Eas 1 m EE R? m {5 m is :2 N if: o=

I J W INVENTOR:

- CONSTANT MARTIN.

ATTORNEY.

P 25, 1951 c. MARTIN 2,568,862

ELECTRICAL MUSICAL INSTRUMENT WITH VIBRATORYI STRINGS Filed Aug. 13,1947 5 Sheets-Sheet 2 Fig. 2

VARIABLE. RESISTANCE [AMPLIFIER I AMPLIFIER Fig.3

VARIABLE RES! STAN CE. AMPLIFIE INVENTOR:

dons-mm mun-m.

ATTORNEY Sept. 25, 1951 Q MARTIN 2,568,862

ELECTRICAL MUSICAL INSTRUMENT WITH VIBRATORY STRINGS Patented Sept. 25,1951 ELECTRICAL MUSICAL INSTRUMENT WITH VIBRATORY STRINGS ConstantMartin, Versailles, France Application August 13, 1947, Serial No.768,403 In France August 14, 1946 8 Claims. 1

It is well known that, in a string stretched between two fixed points,if an intermediate point of said string is struck with a movable nut orhammer which remains applied against the string, both portions of thelatter as determined by the nut or hammer start vibrating separately.Such vibrations become gradually damped and the time required for suchdamping depends on the nature of the hammer, on its mass and on theinertia of any parts rigid with said hammer. When the hammer leaves thestring and there is no damper provided, the string continues to vibratethroughout its entir length until completely damped out.

The present invention has for its object to provide a musical instrumentwith vibratory strings which initially utilises the above describedphenomenon associated with one or more other phenomena. of electrical oracoustical nature.

It consists of using a. vibrator string made of an electricallyconductive material, stretched be tween two points and which is struckat an intermediate point thereof with a movable nut or a hammer ofsuitably predetermined mass and character, wherein said hammer may beoperated either directly or indirectly through any suitable device suchas a key of a key-board or the like, and wherein said hammer may,through any appropriate mechanism be caused when desired by theperformer, to remain applied against the string as the performerreleases the device, key or the like, controlling the operation of themovable nut.

The invention also includes the damping or throttling by means of asuitable damping sys- I tem, the vibrations of one portion of the stringso as to use only the vibrations of the other portion. Such acousticvibrations of the second portion of the string are converted intoelectric vibrations which are then amplified in an amplifier andreconverted into sound vibrations by means of a loud speaker or anyother appropriate means.

In order to prolong the vibrations of that portion of the string whichis used, a second movable nut or hammer, operated by any suitablecontrolmember, is adapted to be applied against the string at the samepoint as the first hammer or nut, and remains applied thereagainst asthe first nut leaves the string and returns to its rest position. Alsowith the purpose of prolonging the vibrations of the string, anotherstring stretched between two fixed points and tuned. to the samefrequency as the main string is caused to vibrate by resonance as saidfirst string vibrates. The vibrations of the second string may also beconverted into electric vibrations and amplified and transmitted to aloud-speaker.

The instrument forming the subject matter of this patent applicationcomprises as many elementary devices of the above defined type as may bedesired, tuned to the frequencies of one or more octaves of the musicalscale, and thus makes it possible to play any desired piece of musicalliterature.

An embodiment of one of the elements comprising the instrument will nowbe described by way of illustration and not of limitation:

Fig. 1 diagrammatically illustrates such an elementary device;

Fig. 2 diagrammatically illustrates a modification of the device shownin Fig. l.

Fig. 3 diagrammatically illustrates a second embodiment of the deviceshown in Fig. 1.

Fig. 4 illustrates diagrammatically a device similar to that shown inFig. 1 provided with a plurality of elements enabling a vibratory stringto be struck at dillerent points so as to secure several musical noteswith a single string.

The above figures are given merely by way of example and the devicesshown therein are not to be construed as limiting the invention, whichmay further comprise any variations and modifications in accordance withthe spirit thereof.

As may be seen in Fig. 1, the initial vibratory strin is stretchedbetween two points A and B. The hammer or movable nut I is selected witha suitable mass so that the vibrations of the portion CB of thevibratory string will be damped after a sufiiciently long time, whensaid hammer or nut is maintained applied against the string at a pointC.

A lever 2 movable around a pivot 3 carries the hammer or nut I. The endI of the lever 2 is bevelled. A blocking device is provided to block thenut I in the position wherein it is in contact with the vibratorystring. Said blocking device comprises a part 9 movable about the pivotI0 and one end I I of which carries a bent plate 8 adapted to latch thelever 2, thereby holding the nut I in contact with the vibrator string.

A secondary hammer or movable nut l4 the end I5 of which is providedwith a vibrationdamping material is secured to a lever I2 movable aboutthe pivot I3. Said secondary nut may be held in or out of contactengagement with the string at the point C opposite to the main orprimary nut I.

The damper 6 may be made of felt, cloth, sponge rubber or any othersuitable material and O is in permanent contact engagement with thestring portion AC.

The electric portion of the elementary device comprises a coil 4surrounding a magnet core 5 spaced a short distance away from the springportion CD and in such a way that the vibrations of the latter areeffective to modify the reluctance of the magnetic circuit of the magnet5.

The electric circuit for the induction coil '4 is closed through apotentiometer or a variable resistance l5 through the medium oftheportion CD of the vibratory string and the switchmeans formed by the nutI in contact with the string AB at the point C.

A shunt switch I makes it possible tocause.

the last mentioned switch means to b ineffece tive.

The electric vibrations induced through the coil 4 and the power ofwhich is adjustable by the potentiometer orvariable resistor l6 are fedthrough an amplifier I? and are then converted into sound vibrations inthe loud-speaker I8.

Finally, a string DE stretched a short distance away'from AB and tunedto the same frequency asthe active portion GB of: the string, AB

may be caused to resonate with CB when a damper I9 carried by a leverZSJmoVable about its pivot 2| is out of contact with the string. Amagnetic core 26 surroundedby a coil 23 is spaced ashort distance fromthe string DE and the output of thecoil 23 is connected throughthemedium of a variable resistance 25 to the input of the amplifier 26followed by a loud speaker 27.

The elementary device described above operates as follows:

The player presses on the end of the lever 2 opposite to the nut. Underthe impact of the nut, the portion GB of the stringstarts vibrating. Thecoil 4 then becomes the seat of induced'currents therethrough whichafteramplification in the amplifier 1'. actuate the loud speaker I8..The sound is prolonged until complete damping of the vibrations in thestring portion CB, if the nut is held in contact with the string. Thvolume of the sound is the greater as the impact of the nut against theString has been stronger and is therefore variable according to theplayers desire. The sound is brief if the performerallows the nut todrop back immediately after having struck the string, the vibrations inthe latter then being stopped immediately.

In the event where thesound is to be prolonged and in order to free theplayers finger, the device comprising the parts 8, 9, l0, blocks thelever 2 in its lowermost position and consequently blocks the nut l Theoperation of the latching device may be controlled through a pedal orany other suitable,

means, andin the latched position thus obtained it is possible, lay-oncemore striking the lever 2, to cause a further extension in the durationof the sound, and the production of particular musical effects.

The performer may also extend the duration of the sound by means of thesecondary nut [5. That is, by closing the switch I and bringing thesecondary nut 15 into contact with the string, any impact however brief,of the main nut 1 causes vibration. of spring portion CB, the dampingtime of which depends on the character of the secondary nut E4 and ofits support as well as on the. pressure exerted thereby against thestring, if'its end I5 is provided with aresilient material. Like thedevice described in the foreagainst the vibratory string.

going paragraph, this device may also be operated by means of levers orany other appropriate means.

Finally, a resonant system may also be caused to extend the vibrationsof the string portion CB and the resonance of the secondary string DE isallowed to be effective by retracting, as desired by the performer, thedamper l9. An electric ystem similar to that provided for the mainstring AB picks up and amplifies the vibrations of the secondary string.

In the modification of Fig. 2 the resonant string DE is electricallycontrolled through the amplifier H of Fig. 1.

Part of the available energy at the output of theamplifier l! is appliedto the string DE, arranged between the arms NS of a magnet. The stringDE is therefore energized each time the portion CB of the string of Fig.1 is caused to vibrate. A pick-up-amplifier-control and loudspeaker-rassembly 29.303l--32 identical with the assembly 23-252 3 21 ofFig. 1 converts asbefore the-vibrations of the string.

In the modification shown in Fig. 3 asimilar' result is obtained byreinforcing the-resonance energization of the strings such as DE withone or more loud speakers33 which receive a fraction ofthe.available-energy fromgthe output of the,

amplifier I! of Fig. 1.1 The vibrations of the strings such as DE areconverted as before in an assembly 35353T-38.

Anarrangementadapted to provide for the se-v curing of several noteswith a single string, is i1- lustrated in Fig. 4. In this arrangement,which is 'in'principle similar to that illustrated and described, withreference to Fig. 1, a plurality; of hammers or nuts areprovided atspaced points along the vibratory string AmBm.- In Fig. 4,

three hammers or'nuts la,- lb, and I0, are showm eachiactuated bylevers2a, 2b, and 2c, respectively;which levers are pivoted as at 3a, 3b,. and3c; blocking -devices9a, 9b, and 9c, are pivoted at lila, lob, and IUc,and carrying; at ends Ha, I lb; andjl lc, respectively, the bent plates8a, 8b, andBc; respectively. In general, therefore, the construction ofithe arrangement illustrated in Fig.,4-is identical with thatillustrated and described with reference to Fig. l, with the differencethat-instead of a single hammer I being provided with accompanyingattachments, three hammers, la, I b, and 10 are provided. The electricalcircuit provided is similar to that illustrated with respect to Fig. l,the principal parts'carrying the same reference numbers followed by theletter m.. It will be appreciated that the number of hammers or nuts isnot limited to three.

Numerous modifications other than those described herein may readily bedevised; Such modifications all derive from the foregoing example. Thusit is possible to make use not only of electro-magnetic systems but alsoelectro-static, electro-dynamic, photo-electric, piezo-electric andother means.

It is also possible for greater simplicity and in thecase of Figs. 2 and3 to use a single magnetic core such as 29 or 35 for a plurality ofstrings- Such a core will then be appropriately adapted.

Similarly the feature of disposing the nuts in different ways withrespect to the vibratory string is to be considered as implyingmodification of the present invention, and also the number of said nutsis of no consequence to th present invention.

Furthermore, the position of the nut l in Fig. 1 may be varied and themovable nut or nuts may have any type of motion imparted thereto alongthe string without such a procedure exceeding the scope of the presentinvention. In'thiS way special sound effects may be obtained.

According to the invention, smooth strings and extruded or ribbedstrings maybe used and in the. latter case a, simple displacement of thenut along the string will sustain the vibrations thereof.

The nuts described in the foregoing disclosure may be simply constitutedby the fingers of the performer, without exceeding the scope of thepresent invention.

It is also possible to embody an instrument in accordance with thepresent invention which also comprises a small number of strings, thevarious notes in the scale being obtained by the use of a plurality ofnuts arranged at various points along a. common string.

In as much as a number of modifications may g be made in the foregoingconstruction and the invention is capable of being embodied in a greatnumber of apparently widely diiferent forms without exceeding the scopeof this invention as defined in the appended claims, all detailsmentioned in the foregoing disclosure or shown in the accompanyingdrawings should be regarded as exemplifying and not as limiting thescope of the present invention.

What I claim is:

1. In an electric musical instrument a sound unit comprising incombination a vibratory string, a hammer for striking said string at anintermediate point thereof, hand-controlled actuating means for saidhammer, means for selectively causing said hammer to disengage saidstring immediately after having struck the same and for causing saidhammer to remain in engagement with said string, means for damping thesound vibrations set up in one side of said string, and means forelectrically picking up, amplifying and reconverting into sound thesound vibrations set up in the other side of said string.

2. In an electric musical instrument a sound unit comprising incombination a vibrator string V adapted to vibrate at a desired audiblefrequency, a hammer for striking said string at an intermediate pointthereof, hand-controlled actuating means for said hammer, latching meansoperable for latching said hammer in contact engagement with saidstring, means for damping the sound vibrations set up in one side ofsaid string, and electric means for picking up, amplifying andreconverting into sound waves the vibrations set up in the other side ofsaid string.

3. In an electric musical instrument a sound unit comprising incombination a vibratory string made of an electrically conductivematerial, a hammer of electrically conductive material and actuatingmeans to cause said hammer to strike said string at an intermediatepoint of the length thereof, means for damping the sound vibrations setup in one side of said string, a magnetic core in reluctance-responsiverelation with said string at the other side thereof with reference tosaid intermediate point thereon, an induction coil surrounding saidcore, induction circuit connections for said coil extending through saidstring and said hammer so as to make said circuit as said hammer is incontact engagement with said string, volume-control adjustableresistance means in said circuit, an amplifier input in said circuit anda loud-speaker across the output of said amplifier.

4. In an electric musical instrument a sound unit comprising incombination a vibratory string, a hammer for striking said string at anintermediate point thereof, both said string and said hammer consistingof electrically conductive material, hand-controlled actuating means forsaid hammer and means for blockingsaid hammer in actuated position,means for damping the sound vibrations in one side of said string, a magnetic core in reluctance-responsive relation with said string on theother side of said intermediate point thereof, an induction coilsurrounding said core, circuit connections for said coil extendingthrough said string and said hammer so as to be operative when saidhammer is in said actuated string-engaging position, sound-volumecontrol adjustable resistance means in said circuit, an amplifier inputin said circuit and a loud-speaker across the output of said amplifier.

5. In an electric musical instrument a sound unit comprising incombination a vibratory string of conductive material, a hammer ofconductive material adapted to strike said string at an intermediatepoint thereof, a second hammer actuatable to strike said stringsubstantially at the same point thereof, means for damping the soundvibrations in one side of said string, a magnetic core in closely spacedrelation with a point of said string on the other side of saidintermediate point, an induction coil surroundin said core, circuitconnections for said coil extending through said string and said hammerso as to be closed when said first hammer is in string-engagingposition, a manually operable shorting switch in shunt across said firsthammer and said string to allow said circuit to be closed when saidfirst hammer is out of contact while said second hammer is in contactwith said string, sound-volume potentiometer control means in saidcircuit, an amplifier the input to which is in said circuit and aloud-speaker across the output of said amplifier.

6. In an electric musical instrument a sound unit comprising incombination a first vibratory string, means for striking said string atan intermediate point thereof, means for damping the vibrations in oneside of said string, pick-up means for converting the vibrations in theother side of said string into corresponding electric oscillations,means for amplifying said oscillations and means for reconverting saidamplified oscillations into sound, a second string resonant with saidfirst string, means for directing a part of said amplified andreconverted sound energy as derived from said first string to saidsecond string, means for picking up, amplifying and reconverting intosound the resonant vibrations of said second string, and means fordamping the vibrations of said second string.

7. In an electric musical instrument a sound unit comprising incombination a, first vibratory string, means for striking said String atan intermediate point thereof, means for damping the vibrations in oneside of said string, pick-up means for converting the vibrations in theother side of said string into electric oscillations means foramplifying said oscillations, means for reconverting said oscillationsinto sound, a second vibratory string of electrically conductivematerial resonant with said first string, means for supplying a part ofsaid amplified electrical oscillations derived from said first stringacross said second string, pick-up means for converting the vibrationsin said second string into electric oscillations means for amplifyingsaid oscillations and means for reconverting them into sound.

8. An electric musical device comprising a 7 8 string, 'a. plurality ofmeans for striking said REFERENCES CITED string at Spaced pomtsthereamng means for The following references are of record in thedamping the vibrations in one portion of said fil f this patent; stringon one side of each of said points, means for picking up, convertinginto lectric oscilla- 5 UNITED STATES PATENTS tions, amplifying andreconverting into sound Number Name Date the vibrations in the otherside of said string with 472,019 Ohms-rt Mar. 29, 1892 reference to eachof said points, said points be- 716,034 Harriss et a1. Dec. 16, 1902 mgso interrelated along said string as to pro- ,988,564 Nernst Jan. 1 5vide a desired scale or notes. 10 2,001,7 3 Hamm nd M y 2 1 2,185,734Loar Jan. 2, 1940 CONSTANT MARTIN.

